Casein and α-lactalbumin (α-LA) are the main allergens in cow's milk, which can affect the skin, respiratory system, and gastrointestinal tract, even cause anaphylactic shock. Developing a rapid and sensitive detection method of casein and α-LA is still pursued. Herein, a surface-enhanced Raman scattering based lateral flow assay (SERS-LFA) method for rapid and highly sensitive detection of milk allergens in food was established for effectively preventing allergic symptoms. [email protected] nanoparticles ([email protected] NPs) were synthesized as SERS active substrate to prepare the antibody-modified SERS Probe and SERS-LFA strips toward casein and α-LA were assembled according to the sandwich mode. The detection results were calculated according to colorimetric and Raman signal. The introduction of SRES signal significantly increased the sensitivity of detection with the limit of detection (LOD) of 0.19 ng/mL and 1.74 pg/mL, and exhibited an excellent linear relationship within the range of 0.55–791.50 ng/mL and 0.1 pg/mL–100.0 ng/mL for casein and α-LA, respectively. Furthermore, SERS-LFA strips was highly specific with the recovery rates for corresponding 80.36 %–105.12 % and 85.73 %–118.22 % for casein and α-LA, respectively. Therefore, the SERS-LFA could be in great potential to develop a unique allergen detection method.
Aerial cultivation is a convenient method to propagate bulblets. To date, there are few studies on Lilium lancifolium (L. lancifolium) adventitious bulblet formation on bulb scales by aerial cultivation. We used the aerial culture method to study the process of exogenous 6-BA on bulblets formation. Through continuous observation of the bulblets formation process, the changes of endogenous hormones during the bulblets formation process and their correlation with gene expression were analyzed. In this study, we showed that exogenous 50 mg/L 6-BA was the most suitable concentration for bulblets formation in aerial cultivation which the bulblets formation rate was highest. Treatment with exogenous 50 mg/L 6-BA resulted in cell proliferation and a large aggregation of nuclei towards thin-walled cells, thus inducing the formation of bulblets and shorting the formation time of bulblets. The higher the ratio of iPA/ABA, DHZR/ABA, (iPA + DHZR + ZR)/ABA and (iPA + DHZR + ZR)/IAA were the better the induction of bulblets formation. qRT-PCR revealed that exogenous 50 mg/L 6-BA treatment induces bulblets formation by activating the expression of cytokinin receptors AHK2/3/4, activating ARR1/2/12 via AHP1, upregulating the expression of related genes involved in signaling and regulating downstream signaling.
Climate change is altering flood risk globally. The nature of those alterations varies locally, creating the need for regional assessments to inform flood-risk management and planning. This study projects future changes in flood regime in the Yangtze River basin. To characterize flood regimes, we use a multi-attribute approach that measures the relative change in flood magnitude, timing, frequency, and duration between historical and future periods. We use climate projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to force the Soil and Water Assessment Tool (SWAT), and generate daily streamflow projections along the Yangtze River network for two Shared Socioeconomic Pathways (SSPs), SSP2-4.5 and SSP5-8.5. We use seasonal maxima, annual maxima, and peaks-over-threshold to determine the different flood attributes. Results show that downscaled CMIP6 precipitation and near-surface temperature are both projected to increase substantially in the future, with a consequent surge in floods across the basin. In the far future (years 2061-2100), under SSP5-8.5, averaged annual flood magnitude, timing, frequency, and duration are projected to increase 66.6%, arrive 1.9 days earlier, increase 27.5%, and prolong 19.1 days, respectively. Projected changes in flood attributes at annual timescale is generally higher in the northern tributaries as compared to the southern ones. Changes in flood magnitude and frequency tend to resemble each other, whereas flood timing and duration exhibit distinct change patterns. Our multi-attribute approach to flood regime characterization provides a systematic way for translating raw CMIP6 projections into informative future flood projections. This approach can help inform flood-risk planning and improve the reliability of climate change impact assessment.
At present, scholars have mostly discussed urban residents’ public bicycle travel behaviour and the effect of built environment; however, relevant research on college students is insufficient, and a thinking path for the construction of university towns is lacking. On the basis of questionnaire survey and point-of-interest data and taking Xianlin University Town in Nanjing, China as an example, this paper focuses on the spatiotemporal characteristics of college students’ public bicycle travel and the influencing factors of its built environment. Results of multiple logistic regression model show that (1) travel area is related to the campus layout and the number of surrounding commercial facilities, railway stations or bus stops. (2) Travel time period is related to the number of surrounding public facilities or bus stops. (3) Travel duration is related to the campus layout and the number of surrounding public facilities or bus stops. Finally, this paper proposes some suggestions from the aspects of space optimisation layout of public bicycle stations and vehicle space–time scheduling, campus internal space function adjustment and public service facility construction.
People often make personality attribution from facial emotional cues. Previous studies have demonstrated the importance of the valence of facial expressions on personality attribution. However, authenticity is an essential dimension of facial expressions, and it is more important to know how does facial authenticity affect personality attribution. This study combined the personality judgments task and eye-tracking methods to explore the effect of valence and authenticity of expressions on personality attribution and the visual reasoning modes in different expressions. Results showed that expressions with more spontaneous and positive were more likely to be considered kind and competent. Facial expressions affected the extent to which gaze was directed toward the eyebrows for kindness and the mouth for competence. These results suggest that personality attribution is influenced by facial emotional cues, such as valence and authenticity, and this effect is mapped onto specific face regions related to the personality.
Carbon-based CsPbIBr2 perovskite solar cells (PSCs) have attracted much attention due to their excellent photoelectric properties and low cost fabrication processes. The TiO2 has been diffusely employed as electron-transporting layer (ETL) for carbon-based CsPbIBr2 PSC. However, the lower electron mobility for TiO2 restricts the performance improvement. The tactics of ion doping is normally used to improve the ETL performance. In this study, Li-doped TiO2 (Li: TiO2) is used as a novel ETL for carbon-based planar CsPbIBr2 PSC. There is no change in the optical band gap of TiO2 after the incorporation of Li. However, Li-doping can effectively improve the crystallinity of TiO2 film and reduce the dark current and charge recombination of CsPbIBr2 PSC. Comparing with the TiO2-based CsPbIBr2 PSC, the efficiency of CsPbIBr2 PSC with the Li: TiO2 ETL increases from 6.63% to 8.09%. Additionally, the use of the Li: TiO2 ETL also has a positive impact on the long-term stability of the CsPbIBr2 PSC. This work indicates that ion doping can offer a new route to produce effective ETL for the development of highly-efficient CsPbIBr2 solar cell with a interface engineering concept.
The discovery of hominoids dated to the Middle–Late Miocene in the southeastern Tibetan Plateau (SE TP) has attracted widespread attention and highlighted the significance of the SE TP as an important refuge for hominoids. However, research on the living environment of hominoids in the region has primarily focused on the Late Miocene, and there are solely few earlier records on earlier migrations. A recently investigated sedimentary sequence within the Xiaolongtan Basin in the SE TP, which contains two hominoid-bearing levels dated respectively to 12.5 Ma and 11.7 Ma, provides a unique window to characterize and understand the living environment that attracted hominoids to the region. The clay mineral, geochemical and sedimentary analyses of the sequence, characterized by the highest kaolinite content and chemical weathering intensity and the coeval occurrence of thick lignite layers during ∼ 12.6–11.6 Ma, suggest that the climate when hominoids occupied the area was hot with higher humidity compared to the preceding and succeeding intervals. A spatiotemporal analysis of the hominoid distribution in the SE TP and the adjacent Indo-China Peninsula indicates a north–south–north pattern of movement, with their ages of ∼ 13–12.5 Ma, ∼11 to 8–7 Ma, and after ∼ 8–7 Ma. These movements accord roughly with the timing of the advance and retreat of the South Asian monsoon (SAM). We therefore infer that, against the overall cooling climatic trend of the Middle–Late Miocene, the increased precipitation and flourishing vegetation promoted by the SAM expansion, was the principal factor that attracted the hominoids to the region. Overall, our results provide new insights into the relationship between the paleoenvironment and hominoid migration/settlement.
Terpenoids and steroids are two large families of natural products with diverse biological activities. C3 oxidase and acetyltransferase are the key enzymes in the post-modification of terpenoids and steroids, while their discovery is of great importance for the efficient bioproduction and wide application of these natural products. In this review, we first explain the reaction mechanism of typical enzymes. Next, we summarize the current state-of-art strategies in the discovery of C3 oxidase and acetyltransferase, and discuss rational engineering of these enzymes with novel catalytic functions. Finally, we propose how to obtain an excellent biocatalyst of C3 oxidase and acetyltransferase by exploiting the discovery strategy and the reaction mechanism.
Rational design of hetero-diatomic catalysts (DACs) with tunable electronic structures is an effective approach to accelerate the sluggish kinetics of oxygen reduction reaction (ORR) in metal-air batteries and proton-exchange membrane fuel cells (PEMFCs), which, however, still remains a great challenge to date. Herein, we propose a novel multi-step collaborative synthesis strategy to fabricate the N-bridged Fe and Cu diatomic electrocatalysts (Fe, Cu DAs-NC). Benefitting from the inter-atomic electron transfer and robust graphitized structure, the optimized Fe, Cu DAs-NC catalyst exhibits significantly enhanced ORR performances in both alkaline and acidic media, featuring the half-wave potentials of 0.94 V and 0.80 V, respectively. The established solid-state flexible Zn-air battery and H2-O2 single fuel cell using Fe, Cu DAs-NC as cathode deliver an extra-high power density of 83 mW cm⁻² and a maximum power output of 875 mW cm⁻², respectively. In-situ Raman spectroscopy and density functional theory calculations reveal that the strong synergistic interactions between FeN4 and CuN4 moieties are responsible for the d-orbital shift of the atomic Fe and Cu sites and charge polarization between them in the N-bridged coordination environment, which results in the well-defined and favorable adsorption free energy regulations and consequent much enhanced catalytic activity of the diatomic catalysts.
This study explored the predictive relations between executive function and second language vocabulary. Data on receptive and expressive vocabulary in Mandarin and on working memory, inhibitory control, and cognitive flexibility were collected in two waves within a year from 186 Uyghur-Mandarin bilingual preschoolers in China. The results indicated that the predictive relations between executive function and second language vocabulary differed between receptive and expressive vocabulary and were mainly found in inhibitory control and cognitive flexibility. Specifically, inhibitory control and cognitive flexibility in Wave 1 significantly positively predicted Mandarin receptive vocabulary but not expressive vocabulary in Wave 2, whereas Mandarin expressive but not receptive vocabulary in Wave 1 significantly positively directly predicted inhibitory control and cognitive flexibility in Wave 2. Predictive relations between working memory and Mandarin receptive and expressive vocabulary were insignificant. These findings contribute significantly to understanding second language learning, especially Mandarin learning among Uyghur preschoolers in China.
Monochasma savatieri Franch. ex Maxim is a perennial medicinal plant with antibiotic properties. However, the current M. savatieri resources cannot meet the increasing market demand. Thus, an advanced bioengineering technology platform is required for breeding novel and high-yielding M. savatieri germplasm/cultivars with high value. In the present study, a hairy root system induced by Agrobacterium rhizogenes, which is often used as a model to study root function and bioactive compound production, was established for M. savatieri for the first time. The hairy root induction frequencies of the different explants ranged from 4.6% to 68.3% after infection with A. rhizogenes strain LBA9402. Furthermore, many co-transformed hairy root lines using the binary vector pEG100–35S::GFP were generated. Fluorescence microscopy revealed that GFP was expressed in 72.9% of the transgenic hairy root lines. After six months, the co-transformed hairy root lines were able to grow into transgenic plantlets on medium containing cytokinin. In addition, to construct a gene editing system for M. savatieri, the tRNA-target-gRNA cassette was cloned into the pRGEB31 vector with AtU6-sgRNA and hSpCas9 backbones. The cellulose synthase-like D (CSLD2/3) genes were used as markers to assess the gene editing efficiency of the CRISPR/Cas9 vector in M. savatieri. The results showed that the CSLD2/3 sequences were altered in 11 out of 59 co-transformed hairy root lines. This study successfully established a genome editing platform for M. savatieri, for the first time, using the A. rhizogenes-mediated co-transformation system. This will enable the development of novel M. savatieri germplasm/cultivars for facility cultivation and exploitation of its medicinal value in the future.
Rice is one of the most important food crops in Asia. Genetic analyses of complex traits and molecular breeding studies in rice greatly rely on the construction of various genetic populations. Chromosome segment substitution lines (CSSLs) serve as a powerful genetic population for quantitative trait locus (QTL) mapping in rice. Moreover, CSSLs containing target genomic regions can be used as improved varieties in rice breeding. In this study, we developed a set of CSSLs consisting of 117 lines derived from the recipient ‘Huanghuazhan’ (HHZ) and the donor ‘Basmati Surkb 89–15’ (BAS). The 117 lines were extensively genotyped by whole-genome resequencing, and a high-density genotype map was constructed for the CSSL population. The 117 CSSLs covered 99.78% of the BAS genome. Each line contained a single segment, and the average segment length was 6.02 Mb. Using the CSSL population, we investigated three agronomic traits in Shanghai and Hangzhou, China, and a total of 25 QTLs were detected in both environments. Among those QTLs, we found that RFT1 was the causal gene for heading date variance between HHZ and BAS. RFT1 from BAS was found to contain a loss-of-function allele based on yeast two-hybrid assay, and its causal variation was a P to S change in the 94th amino acid of the RFT1 protein. The combination of high-throughput genotyping and marker-assisted selection (MAS) is a highly efficient way to construct CSSLs in rice, and extensively genotyped CSSLs will be a powerful tool for the genetic mapping of agronomic traits and molecular breeding for target QTLs/genes.
The properties of dynamic interactions in mobile-interactive systems are still difficult to analyze because of the complexity of systems. Thus, we have proposed a new Petri net called the variable petri net (VPN) recently, which specializes in describing dynamic interactions in systems. To make better use of VPN, this article focuses on the model checking method of VPN. It introduces the algorithm to transform a VPN to a Kripke structure that can describe both the system running states and the system connection states in VPN, and the method to transform a property to a temporal logic formula based on VPN and its Kripke structure. The Kripke structure can be optimized by considering the specific property about the system connection states and then be used to perform the targeted verification to the property by using a model checker. A practical example is given to demonstrate the proposed methods.
Wind driven optimization (WDO) is a meta-heuristic algorithm based on swarm intelligence. The original selection method makes it easy to converge prematurely and trap in local optima. Maintaining population diversity can solve this problem well. Therefore, we introduce a new fitness-distance balance-based selection strategy to replace the original selection method, and add chaotic local search with selecting chaotic map based on memory to further improve the search performance of the algorithm. A chaotic wind driven optimization with fitness-distance balance strategy is proposed, called CFDBWDO. In the experimental section, we find the optimal parameter settings for the proposed algorithm. To verify the effect of the algorithm, we conduct comparative experiments on the CEC 2017 benchmark functions. The experimental results denote that the proposed algorithm has superior performance. Compared with WDO, CFDBWDO can gradually converge in function optimization. We further verify the practicality of the proposed algorithm with six real-world optimization problems, and the obtained results are all better than other algorithms.
A growing body of research suggests that mathematical anxiety (MA) seriously affects an individual’s math achievement. However, few studies have focused on the cognitive mechanisms of MA in elementary school children. Based on attention control theory (ACT), this research aimed to explore the cognitive mechanism of MA in elementary school children using two studies. In Study 1, the dual-task paradigm of number memory and computation span was used to investigate the difference in processing efficiency between the high-mathematical anxiety (HMA) group and the low-mathematical anxiety (LMA) group. In total, 59 students with HMA and 54 students with LMA participated in Study 1. The results showed that students with HMA had lower processing efficiency in dealing with high-load math tasks. To further investigate the underlying mechanism of low processing efficiency for students with HMA, Study 2 explored the attention bias toward math-related stimuli of students with HMA using the Posner paradigm. In total, 48 students with HMA and 49 students with LMA participated in Study 2. The results showed that math trials put children with HMA in a state of heightened vigilance in general, which might be related to the low processing efficiency in dealing with high-load math tasks. These findings support the ACT and further reveal the mechanism of MA in elementary school children from a cognitive perspective.
A novel dual priority strategy of strengthening charge compensation in A-site of perovskite structure and widening bandgap width was designed to prepare (Ba0.98-xLi0.02Lax)(Mg0.04Ti0.96)O3 (BLLMTx) ceramics, which can solve the conflict between polarization and breakdown strength, and improve the pulse energy storage performance of the BaTiO3-based system. As a result, ultrahigh discharge energy density of 3.98 J/cm³ and giant pulse power density of 321.6 MW/cm³ with current density of 2786.4 A/cm² are obtained at 360 kV/cm for the (Ba0.94Li0.02La0.04)(Mg0.04Ti0.96)O3 (BLLMT0.04) ceramics with considerable fast discharge rate and outstanding temperature stability as well as cycle life, correlating with multi-ferroelectric phases coexistence, increasing bandgap width, strengthening charge compensation and establishing small size of the polar nano-regions (PNRs), which exceeds the great mass of reported lead-free ceramics. The comprehensive properties indicate that the BLLMT0.04 ceramics present potential application in pulse energy storage system. The concept of composition design via increasing bandgap width and strengthening charge compensation provides a new idea for developing lead-free dielectric ceramic capacitors.
Monopile-supported offshore wind turbines (OWTs) inevitably undergo the coupled effects of long-term cyclic loads and scour, resulting in cumulative deformation and the migration of the natural frequency of the foundation-superstructure system and the simultaneous development of scour holes around monopiles, which brings notable challenges to the design of OWTs. Hence, a series of model tests on monopile-supported OWTs in sands were conducted in a flume equipped with a custom long-term cyclic loading device. The mechanical responses of the OWT system and the scour process under separate and coupled effects of long-term cyclic loading and scour were studied, with special attention given to the cumulative rotation, natural frequency, ultimate bearing capacity of the OWT system, and scour hole development. A preliminary investigation of the armoring effect of the overlying coarse-grained soil under combined action was also conducted. The experimental results revealed that the coupled effect of long-term cyclic loading and scour not only has a great impact on the mechanical response of the foundation-superstructure system, but it also resulted in an acceleration of the initial scour rate and reduced the equilibrium scour depth. Moreover, the coupled effect reduced the scour resistance of coarse-grained soils under the layered soil conditions.
Food security is one of the main challenges facing humanity, and increasing crop yields is critical to meet the growing global food demand. Grain production in China has remarkably improved since its founding in 1949, but the growth remains uneven across regions. The goal of this research was to assess the determinants of the yields of three major food crops (maize, rice, and wheat) in China and the mechanism of their responses to increased crop yields. Boosted regression tree models were created to capture the linked complex predictor-response relationships between crop yields and individual explanatory variables using prefecture-level agricultural statistics in China coupled with geographic data during the period from 1952 to 2017. The results showed that technological inputs (e.g., fertilizers, electricity consumption, and power of agricultural machinery) played a key role in the increase of crop yields, which explained 47%, 39%, and 62% of the variances in the yields of maize, rice, and wheat during the period 1952–2017, respectively. However, the contribution of technology became weaker over time, while the contribution of agro-environmental conditions and structural characteristics of administrative regions became stronger. Partial dependence plots indicated that encouraging higher technological inputs, accelerating large-scale grain production, shortening the urban-rural income gap, and improving the education of farmers were conductive to increasing crop yields. Overall, our results suggest that grain production policies aimed at increasing crop yields should better reflect the spatial heterogeneity of yield gaps; low-yield-gap regions should improve the utilization efficiency of water and fertilizer and formulate measures to inhibit non-grain production on cultivated land, while high-yield-gap regions should focus on improving technological inputs and promoting agricultural restructuring. This study provides deep insights into the processes of how individual explanatory variables affect crop yields, which is essential to develop differentiated grain production policies and provide valuable references for shortening yield gaps in high-yield-gap regions.
We study the cause and consequences of hometown favoritism in industrial land supply, based on the dataset of Chinese land transaction and the birthplaces of Central Committee (CC) members. We find that prefecture cities have more industrial land supply when they are the hometowns of current CC members. Compared to prefecture with no CC members, prefecture with CC members has 214.05 ha more industrial land supply. Having an additional CC member in a prefecture increases the industrial land supply by 5.5 %. We find that political career concern, social ties and culture link drive hometown favoritism. Furthermore, hometown favoritism in industrial land supply can distort the location and structure of industrial land supply, and distort the efficiency of economic development.
Plant root and shoot growth are closely interrelated, though the connotation of root–shoot balance should not be limited to their connectivity in biomass and physiological indicators. Their directional distribution of mass in architecture and the resulting root–shoot interactions are the keys to understanding the dynamic balance of the below- and above-ground organs related to tree anchorage. This study focuses on the 4-year-old camphor tree ( Cinnamomum camphora L.) as a system to observe the biomass distribution in response to the asymmetric disturbance treatments of biased root (BRT), inclined trunk (ITT), and half-crown (HCT) in a controlled cultivation experiment using the minirhizotron technique. We found an inverse relationship of biomass distribution of crowns to roots in BRT and opposite asymmetries of roots with crowns in response to the ITT and HCT treatments. We also observed higher net photosynthesis rate ( P n ), water use efficiency, and chlorophyll content in the leaves on the side opposite the lean in ITT, and higher P n , transpiration rate, and chlorophyll content on the root-bias side in BRT, which is consistent with the nutrient allocation strategies of allocating nutrients across plant organs in an optimal way to obtain ‘functional equilibrium’ and adapt to the stressed environment. Furthermore, the asymmetrical growth transformation of first-level branch length from the root-bias side to the opposite side in BRT, and a similar transformation of root length from the crown-bias side to the opposite side in HCT, imbues further theoretical support of the nutrient allocation strategy and the biomechanical stability principle, respectively. In summary, this study is the first to identify opposite interaction between below- and above-ground biomass distributions of the camphor tree. The findings enrich the connotation of root–shoot interactions and help to realize root design for the silviculture management of urban forests.
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